Digital projectors, such as digital micro-mirror device (DMD) and liquid crystal device (LCD) projectors, project high quality images onto a viewing surface. Both DMD and LCD projectors utilize high intensity lamps and reflectors to generate the light needed for projection. Light generated by the lamp is concentrated as a ‘fireball’ that is located at a focal point of a reflector. Light produced by the fireball is directed into a projection assembly that produces images and utilizes the generated light to project the image onto a viewing surface.
The combination of the lamp and reflector is often referred to as a light engine. Projector systems often include a lamp receiver for coupling the light engine to the projector system. If the light engine is not properly aligned with the projector system, less of the light produced by the light engine is utilized by the projector system in projecting the image. Thus, the image projected has a relatively lower quality in terms of brightness.
As a result, efforts have been directed at ensuring that a lamp holder is properly oriented and aligned with respect to the projector system. One prior solution consists of a lamp receiver with wedged slides that have locating pins on one side. The pins are used to center the lamp holder in one direction and the slides are used to align the tilt and offset. The accuracy of such a lamp receiver is determined, at least in part, by independently formed features that are then assembled.
Each part may be formed with a certain degree of accuracy. The accuracy with which the part can be formed is known as a tolerance. For example, if a part can accurately be formed within +/−0.001 inches of the idealized part shape, it has a tolerance of 0.001 inches. If four such parts are assembled, then the corresponding accuracy of the part is additive, such that the tolerance of the assembly is no more accurate than 0.004 inches in addition to the tolerance associated with putting the assembly together.
As a result, the accuracy of the lamp receiver discussed above depends on the accuracy of each of the independently formed parts and the accuracy of the assembly. The total of these tolerances may become sufficiently large that the image quality suffers. In addition, the formation of such lamp receivers can be time consuming and hence relatively expensive.